One of the earliest cutting instruments known to man were stone knives developed in prehistoric times. These blades were made by pressure flaking selected materials, such as quartz and obsidian, to create an edge of relative sharpness that could be used for cutting, piercing and/or scrapping.
While various advancements were made over time to the art of forming these stone knives, the next historical advancement occurred with the development of various blades out of metals approximately 10,000 years ago. Metals were favored for their durability and malleability and did not exhibit the brittleness of their stone ancestors. Improvements in technology rationally followed with the development of different metals extending chronologically from copper to bronze to iron and steel.
Metallic cutting blades have dominated the state of the art up until the present time. However, recent development in materials science has yielded ceramic materials which in many ways exhibit superior properties over their metallic counterparts as disclosed by the inventors of the within described technology. These advantages when such blades are manufactured according to the methods described herein, include higher edge retaining properties, self sharpening characteristics, non-contaminating properties and the characteristics of cleanliness and sterility, where desired. Accordingly, despite the sucess of metal blades, there remains a long felt need for improved blade devices, and the present invention seeks to satisfy that need.
The need for better cutting edges can be highlighted in the industrial and medical fields. In the industrial arena, substantial costs may be experienced by those who employ metal blades in high use applications. These costs not only include the replacement of a blade part, but also in the maintenance time involved to replace a blade as well as in down time of equipment wherein blades are being replaced. With the growth of the micro-electronics industry, metal blades are less desirable due to the inherent nature of metallic elements to contaminate a semi-conductor device especially where the materials used to form the semi-conductor device have a greater hardness than the hardness of the metal blade so that contact between a crystal and the metallic blade may result in metallic contaminants associating with the semi-conductor crystal.
In medical applications, metal blades have some inherent porosity regardless of how finely crafted the blade is. Thus, although these blades may be sterilized, there is some risk, however small, that an instrument may remain contaminated by viral or other disease causing microbes. Ceramic materials, on the other hand, do not have the porosity of metal; thus, contaminants are more readily removed. Further, due to their high vapor pressure, ceramic blades may be sterilized at temperatures which would melt metallic blades thus increasing the level of sterilization. Accordingly, therefore, there is a modern need for ceramic knives that has only been recently recognized. Further, there is a need for improved technologies both in blade configuration and in construction methodologies therefor. This invention, therefor, is directed toward meeting those needs.